Three years ago, Marriott International had a problem in India.

Water tankers arrived daily at its 32 hotels there, but often with sand and contaminants or with less water than promised. The uncertainty made it hard to manage costs and risk, said Denise Naguib, Marriott’s vice president for sustainability.

While searching for solutions, Naguib’s phone rang. It was Emilio Tenuta, Ecolab’s vice president of corporate sustainability. He wanted Marriott to test a new “water risk monetizer” that the St. Paul water filtration and sanitizing company just co-developed with Microsoft and environmental data firm TruCost.

The free tool would allow Marriott to analyze how much water scarcity and pollution cost their operation.

The upside for Marriott? To make the water safer and to help meet the corporate goal of reducing water use by 20 percent by the year 2020.

For Ecolab, it was a chance to find problems that could be solved by buying Ecolab equipment.

Marriott solved several issues with the project. For example, the company bought an Ecolab automated water-boiler treatment system for the JW Marriott Hotel in Pune, India. The purchase saved 1.1 million gallons of water in six months.

“The monetizer was a phenomenal solution for us,” Naguib said. “It was huge.”

Ecolab launched an updated monetizer worldwide in March in honor of World Water Day.

The tool debuts just as global manufacturing giants such as 3M, Dow Chemical and General Mills race internally and with customers to cut energy and water use amid increasing drought conditions worldwide.

“Here are the hard facts. By 2030 fresh water demand will exceed supplies by 40 percent,” Tenuta said. “That has a dramatic impact to businesses and communities around the world. The challenge is that many water users have limited awareness of the real costs that water presents to their operations.”

To help, the monetizer calculates water bills, water basin data, regulatory and water treatment costs, and other factors to determine the full price of water to company operations. In some cases, data reveals that the chance of regional water shortages, pollution costs and surcharges is so great, the company risks operational delays, hiked costs and wrecked reputations.

Microsoft helped create the water risk monetizer and also gave it a try. In its data center in San Antonio, hundreds of hot computer servers need lots of water to stay cool. Any water availability problem could be disastrous.

“The watershed in San Antonio is highly stressed due to quality and scarcity issues. So we saw the importance of embedding this [monetizer] tool in our own operations,” said Josh Henretig, Microsoft’s senior director of environmental sustainability. “We learned the risk-adjusted water bill from our operation was really 11 times greater than the actual water bill. That helped us make the case that water treatment and recycling was the cost-effective way to go.”

It bought systems from Ecolab and cut water use by 60 million gallons and its water bill by $140,000.

Ecolab, with $13 billion in revenue, won’t disclose the amount of equipment sales it has won as a result of the monetizer. But analysts note that the new tool helps with marketing and syncs well with Ecolab’s traditional services.

Ecolab makes water filters plus sanitizing, cleaning and processing chemicals for hospitality, oil and factory customers around the globe. It also aggressively services customer equipment and analyzes processes so customers can slash energy, water and operating costs, said spokesman Roman Blahoski.

Worries about droughts and dirty water are so great among farmers, city planners and factories that multinational firms, universities, researchers and environmentalists are all studying what more can be done to conserve water, said Kate Brauman, lead scientist for the Global Water Initiative at the University of Minnesota’s Institute on the Environment.

Last year, the U partnered with the Nature Conservancy, the Global Water Policy Project and the Center for Environmental Systems Research to create detailed maps showing watershed depletion zones around the globe. Unlike past efforts, the new maps identified smaller acreages struck by water fluctuations.

The maps, free online, are designed to help farmers, factories and consumers make smarter decisions about water, Brauman said.

“As a society, we don’t measure and monitor our water impact very well,” she said. “The reality is that when you [measure] the monetary impact of water scarcity, that means a company can do something about it.”

In India, the water risk monetizer “gave [Marriott] the ability to really impact our operations and financial effectiveness,” Naguib said. “The studies in India definitely showed a double-digit reduction.”

Monetizer data revealed that Marriott’s true water spending for the 32 India hotels was six times larger than just the monthly water bill. It also showed that 19 of the hotels would save 22 million gallons a day combined if they used Ecolab’s new water 3-D Trasar system to automatically test and treat the corrosive water used in the hotels’ water boilers and cooling towers.

“We’re talking about enough water to fill swimming pools — so that’s a lot of water,” Naguib said.